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// All rights reserved.
//
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// modification, are permitted provided that the following conditions are
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//
//     * Redistributions of source code must retain the above copyright
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// contributors may be used to endorse or promote products derived from
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// Google Mock - a framework for writing C++ mock classes.
//
// This file implements some commonly used actions.

// GOOGLETEST_CM0002 DO NOT DELETE

#ifndef GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
#define GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_

#ifndef _WIN32_WCE
#include <errno.h>
#endif

#include <algorithm>
#include <string>

#include "gmock/internal/gmock-internal-utils.h"
#include "gmock/internal/gmock-port.h"

#if GTEST_LANG_CXX11 // Defined by gtest-port.h via gmock-port.h.
#include <functional>
#include <type_traits>
#endif // GTEST_LANG_CXX11

namespace testing {

// To implement an action Foo, define:
//   1. a class FooAction that implements the ActionInterface interface, and
//   2. a factory function that creates an Action object from a
//      const FooAction*.
//
// The two-level delegation design follows that of Matcher, providing
// consistency for extension developers.  It also eases ownership
// management as Action objects can now be copied like plain values.

namespace internal {

template<typename F1, typename F2>
class ActionAdaptor;

// BuiltInDefaultValueGetter<T, true>::Get() returns a
// default-constructed T value.  BuiltInDefaultValueGetter<T,
// false>::Get() crashes with an error.
//
// This primary template is used when kDefaultConstructible is true.
template<typename T, bool kDefaultConstructible>
struct BuiltInDefaultValueGetter {
    static T Get() { return T(); }
};
template<typename T>
struct BuiltInDefaultValueGetter<T, false> {
    static T Get()
    {
        Assert(false, __FILE__, __LINE__,
               "Default action undefined for the function return type.");
        return internal::Invalid<T>();
        // The above statement will never be reached, but is required in
        // order for this function to compile.
    }
};

// BuiltInDefaultValue<T>::Get() returns the "built-in" default value
// for type T, which is NULL when T is a raw pointer type, 0 when T is
// a numeric type, false when T is bool, or "" when T is string or
// std::string.  In addition, in C++11 and above, it turns a
// default-constructed T value if T is default constructible.  For any
// other type T, the built-in default T value is undefined, and the
// function will abort the process.
template<typename T>
class BuiltInDefaultValue
{
public:
#if GTEST_LANG_CXX11
    // This function returns true iff type T has a built-in default value.
    static bool Exists()
    {
        return ::std::is_default_constructible<T>::value;
    }

    static T Get()
    {
        return BuiltInDefaultValueGetter<
            T, ::std::is_default_constructible<T>::value>::Get();
    }

#else // GTEST_LANG_CXX11
    // This function returns true iff type T has a built-in default value.
    static bool Exists()
    {
        return false;
    }

    static T Get()
    {
        return BuiltInDefaultValueGetter<T, false>::Get();
    }

#endif // GTEST_LANG_CXX11
};

// This partial specialization says that we use the same built-in
// default value for T and const T.
template<typename T>
class BuiltInDefaultValue<const T>
{
public:
    static bool Exists() { return BuiltInDefaultValue<T>::Exists(); }
    static T Get() { return BuiltInDefaultValue<T>::Get(); }
};

// This partial specialization defines the default values for pointer
// types.
template<typename T>
class BuiltInDefaultValue<T *>
{
public:
    static bool Exists() { return true; }
    static T *Get() { return NULL; }
};

// The following specializations define the default values for
// specific types we care about.
#define GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(type, value) \
    template<> \
    class BuiltInDefaultValue<type> \
    { \
    public: \
        static bool Exists() { return true; } \
        static type Get() { return value; } \
    }

GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(void, ); // NOLINT
#if GTEST_HAS_GLOBAL_STRING
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::string, "");
#endif // GTEST_HAS_GLOBAL_STRING
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::std::string, "");
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(bool, false);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned char, '\0');
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed char, '\0');
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(char, '\0');

// There's no need for a default action for signed wchar_t, as that
// type is the same as wchar_t for gcc, and invalid for MSVC.
//
// There's also no need for a default action for unsigned wchar_t, as
// that type is the same as unsigned int for gcc, and invalid for
// MSVC.
#if GMOCK_WCHAR_T_IS_NATIVE_
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(wchar_t, 0U); // NOLINT
#endif

GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned short, 0U); // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed short, 0); // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned int, 0U);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed int, 0);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long, 0UL); // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long, 0L); // NOLINT
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(UInt64, 0);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(Int64, 0);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(float, 0);
GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(double, 0);

#undef GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_

} // namespace internal

// When an unexpected function call is encountered, Google Mock will
// let it return a default value if the user has specified one for its
// return type, or if the return type has a built-in default value;
// otherwise Google Mock won't know what value to return and will have
// to abort the process.
//
// The DefaultValue<T> class allows a user to specify the
// default value for a type T that is both copyable and publicly
// destructible (i.e. anything that can be used as a function return
// type).  The usage is:
//
//   // Sets the default value for type T to be foo.
//   DefaultValue<T>::Set(foo);
template<typename T>
class DefaultValue
{
public:
    // Sets the default value for type T; requires T to be
    // copy-constructable and have a public destructor.
    static void Set(T x)
    {
        delete producer_;
        producer_ = new FixedValueProducer(x);
    }

    // Provides a factory function to be called to generate the default value.
    // This method can be used even if T is only move-constructible, but it is not
    // limited to that case.
    typedef T (*FactoryFunction)();
    static void SetFactory(FactoryFunction factory)
    {
        delete producer_;
        producer_ = new FactoryValueProducer(factory);
    }

    // Unsets the default value for type T.
    static void Clear()
    {
        delete producer_;
        producer_ = NULL;
    }

    // Returns true iff the user has set the default value for type T.
    static bool IsSet() { return producer_ != NULL; }

    // Returns true if T has a default return value set by the user or there
    // exists a built-in default value.
    static bool Exists()
    {
        return IsSet() || internal::BuiltInDefaultValue<T>::Exists();
    }

    // Returns the default value for type T if the user has set one;
    // otherwise returns the built-in default value. Requires that Exists()
    // is true, which ensures that the return value is well-defined.
    static T Get()
    {
        return producer_ == NULL ? internal::BuiltInDefaultValue<T>::Get() : producer_->Produce();
    }

private:
    class ValueProducer
    {
    public:
        virtual ~ValueProducer() {}
        virtual T Produce() = 0;
    };

    class FixedValueProducer : public ValueProducer
    {
    public:
        explicit FixedValueProducer(T value)
            : value_(value)
        {
        }
        virtual T Produce() { return value_; }

    private:
        const T value_;
        GTEST_DISALLOW_COPY_AND_ASSIGN_(FixedValueProducer);
    };

    class FactoryValueProducer : public ValueProducer
    {
    public:
        explicit FactoryValueProducer(FactoryFunction factory)
            : factory_(factory)
        {
        }
        virtual T Produce() { return factory_(); }

    private:
        const FactoryFunction factory_;
        GTEST_DISALLOW_COPY_AND_ASSIGN_(FactoryValueProducer);
    };

    static ValueProducer *producer_;
};

// This partial specialization allows a user to set default values for
// reference types.
template<typename T>
class DefaultValue<T &>
{
public:
    // Sets the default value for type T&.
    static void Set(T &x)
    { // NOLINT
        address_ = &x;
    }

    // Unsets the default value for type T&.
    static void Clear()
    {
        address_ = NULL;
    }

    // Returns true iff the user has set the default value for type T&.
    static bool IsSet() { return address_ != NULL; }

    // Returns true if T has a default return value set by the user or there
    // exists a built-in default value.
    static bool Exists()
    {
        return IsSet() || internal::BuiltInDefaultValue<T &>::Exists();
    }

    // Returns the default value for type T& if the user has set one;
    // otherwise returns the built-in default value if there is one;
    // otherwise aborts the process.
    static T &Get()
    {
        return address_ == NULL ? internal::BuiltInDefaultValue<T &>::Get() : *address_;
    }

private:
    static T *address_;
};

// This specialization allows DefaultValue<void>::Get() to
// compile.
template<>
class DefaultValue<void>
{
public:
    static bool Exists() { return true; }
    static void Get() {}
};

// Points to the user-set default value for type T.
template<typename T>
typename DefaultValue<T>::ValueProducer *DefaultValue<T>::producer_ = NULL;

// Points to the user-set default value for type T&.
template<typename T>
T *DefaultValue<T &>::address_ = NULL;

// Implement this interface to define an action for function type F.
template<typename F>
class ActionInterface
{
public:
    typedef typename internal::Function<F>::Result Result;
    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

    ActionInterface() {}
    virtual ~ActionInterface() {}

    // Performs the action.  This method is not const, as in general an
    // action can have side effects and be stateful.  For example, a
    // get-the-next-element-from-the-collection action will need to
    // remember the current element.
    virtual Result Perform(const ArgumentTuple &args) = 0;

private:
    GTEST_DISALLOW_COPY_AND_ASSIGN_(ActionInterface);
};

// An Action<F> is a copyable and IMMUTABLE (except by assignment)
// object that represents an action to be taken when a mock function
// of type F is called.  The implementation of Action<T> is just a
// linked_ptr to const ActionInterface<T>, so copying is fairly cheap.
// Don't inherit from Action!
//
// You can view an object implementing ActionInterface<F> as a
// concrete action (including its current state), and an Action<F>
// object as a handle to it.
template<typename F>
class Action
{
public:
    typedef typename internal::Function<F>::Result Result;
    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

    // Constructs a null Action.  Needed for storing Action objects in
    // STL containers.
    Action() {}

#if GTEST_LANG_CXX11
    // Construct an Action from a specified callable.
    // This cannot take std::function directly, because then Action would not be
    // directly constructible from lambda (it would require two conversions).
    template<typename G,
             typename = typename ::std::enable_if<
                 ::std::is_constructible<::std::function<F>, G>::value>::type>
    Action(G &&fun)
        : fun_(::std::forward<G>(fun))
    {
    } // NOLINT
#endif

    // Constructs an Action from its implementation.
    explicit Action(ActionInterface<F> *impl)
        : impl_(impl)
    {
    }

    // This constructor allows us to turn an Action<Func> object into an
    // Action<F>, as long as F's arguments can be implicitly converted
    // to Func's and Func's return type can be implicitly converted to
    // F's.
    template<typename Func>
    explicit Action(const Action<Func> &action);

    // Returns true iff this is the DoDefault() action.
    bool IsDoDefault() const
    {
#if GTEST_LANG_CXX11
        return impl_ == nullptr && fun_ == nullptr;
#else
        return impl_ == NULL;
#endif
    }

    // Performs the action.  Note that this method is const even though
    // the corresponding method in ActionInterface is not.  The reason
    // is that a const Action<F> means that it cannot be re-bound to
    // another concrete action, not that the concrete action it binds to
    // cannot change state.  (Think of the difference between a const
    // pointer and a pointer to const.)
    Result Perform(ArgumentTuple args) const
    {
        if (IsDoDefault()) {
            internal::IllegalDoDefault(__FILE__, __LINE__);
        }
#if GTEST_LANG_CXX11
        if (fun_ != nullptr) {
            return internal::Apply(fun_, ::std::move(args));
        }
#endif
        return impl_->Perform(args);
    }

private:
    template<typename F1, typename F2>
    friend class internal::ActionAdaptor;

    template<typename G>
    friend class Action;

    // In C++11, Action can be implemented either as a generic functor (through
    // std::function), or legacy ActionInterface. In C++98, only ActionInterface
    // is available. The invariants are as follows:
    // * in C++98, impl_ is null iff this is the default action
    // * in C++11, at most one of fun_ & impl_ may be nonnull; both are null iff
    //   this is the default action
#if GTEST_LANG_CXX11
    ::std::function<F> fun_;
#endif
    internal::linked_ptr<ActionInterface<F>> impl_;
};

// The PolymorphicAction class template makes it easy to implement a
// polymorphic action (i.e. an action that can be used in mock
// functions of than one type, e.g. Return()).
//
// To define a polymorphic action, a user first provides a COPYABLE
// implementation class that has a Perform() method template:
//
//   class FooAction {
//    public:
//     template <typename Result, typename ArgumentTuple>
//     Result Perform(const ArgumentTuple& args) const {
//       // Processes the arguments and returns a result, using
//       // tr1::get<N>(args) to get the N-th (0-based) argument in the tuple.
//     }
//     ...
//   };
//
// Then the user creates the polymorphic action using
// MakePolymorphicAction(object) where object has type FooAction.  See
// the definition of Return(void) and SetArgumentPointee<N>(value) for
// complete examples.
template<typename Impl>
class PolymorphicAction
{
public:
    explicit PolymorphicAction(const Impl &impl)
        : impl_(impl)
    {
    }

    template<typename F>
    operator Action<F>() const
    {
        return Action<F>(new MonomorphicImpl<F>(impl_));
    }

private:
    template<typename F>
    class MonomorphicImpl : public ActionInterface<F>
    {
    public:
        typedef typename internal::Function<F>::Result Result;
        typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

        explicit MonomorphicImpl(const Impl &impl)
            : impl_(impl)
        {
        }

        virtual Result Perform(const ArgumentTuple &args)
        {
            return impl_.template Perform<Result>(args);
        }

    private:
        Impl impl_;

        GTEST_DISALLOW_ASSIGN_(MonomorphicImpl);
    };

    Impl impl_;

    GTEST_DISALLOW_ASSIGN_(PolymorphicAction);
};

// Creates an Action from its implementation and returns it.  The
// created Action object owns the implementation.
template<typename F>
Action<F> MakeAction(ActionInterface<F> *impl)
{
    return Action<F>(impl);
}

// Creates a polymorphic action from its implementation.  This is
// easier to use than the PolymorphicAction<Impl> constructor as it
// doesn't require you to explicitly write the template argument, e.g.
//
//   MakePolymorphicAction(foo);
// vs
//   PolymorphicAction<TypeOfFoo>(foo);
template<typename Impl>
inline PolymorphicAction<Impl> MakePolymorphicAction(const Impl &impl)
{
    return PolymorphicAction<Impl>(impl);
}

namespace internal {

// Allows an Action<F2> object to pose as an Action<F1>, as long as F2
// and F1 are compatible.
template<typename F1, typename F2>
class ActionAdaptor : public ActionInterface<F1>
{
public:
    typedef typename internal::Function<F1>::Result Result;
    typedef typename internal::Function<F1>::ArgumentTuple ArgumentTuple;

    explicit ActionAdaptor(const Action<F2> &from)
        : impl_(from.impl_)
    {
    }

    virtual Result Perform(const ArgumentTuple &args)
    {
        return impl_->Perform(args);
    }

private:
    const internal::linked_ptr<ActionInterface<F2>> impl_;

    GTEST_DISALLOW_ASSIGN_(ActionAdaptor);
};

// Helper struct to specialize ReturnAction to execute a move instead of a copy
// on return. Useful for move-only types, but could be used on any type.
template<typename T>
struct ByMoveWrapper {
    explicit ByMoveWrapper(T value)
        : payload(internal::move(value))
    {
    }
    T payload;
};

// Implements the polymorphic Return(x) action, which can be used in
// any function that returns the type of x, regardless of the argument
// types.
//
// Note: The value passed into Return must be converted into
// Function<F>::Result when this action is cast to Action<F> rather than
// when that action is performed. This is important in scenarios like
//
// MOCK_METHOD1(Method, T(U));
// ...
// {
//   Foo foo;
//   X x(&foo);
//   EXPECT_CALL(mock, Method(_)).WillOnce(Return(x));
// }
//
// In the example above the variable x holds reference to foo which leaves
// scope and gets destroyed.  If copying X just copies a reference to foo,
// that copy will be left with a hanging reference.  If conversion to T
// makes a copy of foo, the above code is safe. To support that scenario, we
// need to make sure that the type conversion happens inside the EXPECT_CALL
// statement, and conversion of the result of Return to Action<T(U)> is a
// good place for that.
//
// The real life example of the above scenario happens when an invocation
// of gtl::Container() is passed into Return.
//
template<typename R>
class ReturnAction
{
public:
    // Constructs a ReturnAction object from the value to be returned.
    // 'value' is passed by value instead of by const reference in order
    // to allow Return("string literal") to compile.
    explicit ReturnAction(R value)
        : value_(new R(internal::move(value)))
    {
    }

    // This template type conversion operator allows Return(x) to be
    // used in ANY function that returns x's type.
    template<typename F>
    operator Action<F>() const
    {
        // Assert statement belongs here because this is the best place to verify
        // conditions on F. It produces the clearest error messages
        // in most compilers.
        // Impl really belongs in this scope as a local class but can't
        // because MSVC produces duplicate symbols in different translation units
        // in this case. Until MS fixes that bug we put Impl into the class scope
        // and put the typedef both here (for use in assert statement) and
        // in the Impl class. But both definitions must be the same.
        typedef typename Function<F>::Result Result;
        GTEST_COMPILE_ASSERT_(
            !is_reference<Result>::value,
            use_ReturnRef_instead_of_Return_to_return_a_reference);
        return Action<F>(new Impl<R, F>(value_));
    }

private:
    // Implements the Return(x) action for a particular function type F.
    template<typename R_, typename F>
    class Impl : public ActionInterface<F>
    {
    public:
        typedef typename Function<F>::Result Result;
        typedef typename Function<F>::ArgumentTuple ArgumentTuple;

        // The implicit cast is necessary when Result has more than one
        // single-argument constructor (e.g. Result is std::vector<int>) and R
        // has a type conversion operator template.  In that case, value_(value)
        // won't compile as the compiler doesn't known which constructor of
        // Result to call.  ImplicitCast_ forces the compiler to convert R to
        // Result without considering explicit constructors, thus resolving the
        // ambiguity. value_ is then initialized using its copy constructor.
        explicit Impl(const linked_ptr<R> &value)
            : value_before_cast_(*value)
            , value_(ImplicitCast_<Result>(value_before_cast_))
        {
        }

        virtual Result Perform(const ArgumentTuple &) { return value_; }

    private:
        GTEST_COMPILE_ASSERT_(!is_reference<Result>::value,
                              Result_cannot_be_a_reference_type);
        // We save the value before casting just in case it is being cast to a
        // wrapper type.
        R value_before_cast_;
        Result value_;

        GTEST_DISALLOW_COPY_AND_ASSIGN_(Impl);
    };

    // Partially specialize for ByMoveWrapper. This version of ReturnAction will
    // move its contents instead.
    template<typename R_, typename F>
    class Impl<ByMoveWrapper<R_>, F> : public ActionInterface<F>
    {
    public:
        typedef typename Function<F>::Result Result;
        typedef typename Function<F>::ArgumentTuple ArgumentTuple;

        explicit Impl(const linked_ptr<R> &wrapper)
            : performed_(false)
            , wrapper_(wrapper)
        {
        }

        virtual Result Perform(const ArgumentTuple &)
        {
            GTEST_CHECK_(!performed_)
                << "A ByMove() action should only be performed once.";
            performed_ = true;
            return internal::move(wrapper_->payload);
        }

    private:
        bool performed_;
        const linked_ptr<R> wrapper_;

        GTEST_DISALLOW_ASSIGN_(Impl);
    };

    const linked_ptr<R> value_;

    GTEST_DISALLOW_ASSIGN_(ReturnAction);
};

// Implements the ReturnNull() action.
class ReturnNullAction
{
public:
    // Allows ReturnNull() to be used in any pointer-returning function. In C++11
    // this is enforced by returning nullptr, and in non-C++11 by asserting a
    // pointer type on compile time.
    template<typename Result, typename ArgumentTuple>
    static Result Perform(const ArgumentTuple &)
    {
#if GTEST_LANG_CXX11
        return nullptr;
#else
        GTEST_COMPILE_ASSERT_(internal::is_pointer<Result>::value,
                              ReturnNull_can_be_used_to_return_a_pointer_only);
        return NULL;
#endif // GTEST_LANG_CXX11
    }
};

// Implements the Return() action.
class ReturnVoidAction
{
public:
    // Allows Return() to be used in any void-returning function.
    template<typename Result, typename ArgumentTuple>
    static void Perform(const ArgumentTuple &)
    {
        CompileAssertTypesEqual<void, Result>();
    }
};

// Implements the polymorphic ReturnRef(x) action, which can be used
// in any function that returns a reference to the type of x,
// regardless of the argument types.
template<typename T>
class ReturnRefAction
{
public:
    // Constructs a ReturnRefAction object from the reference to be returned.
    explicit ReturnRefAction(T &ref)
        : ref_(ref)
    {
    } // NOLINT

    // This template type conversion operator allows ReturnRef(x) to be
    // used in ANY function that returns a reference to x's type.
    template<typename F>
    operator Action<F>() const
    {
        typedef typename Function<F>::Result Result;
        // Asserts that the function return type is a reference.  This
        // catches the user error of using ReturnRef(x) when Return(x)
        // should be used, and generates some helpful error message.
        GTEST_COMPILE_ASSERT_(internal::is_reference<Result>::value,
                              use_Return_instead_of_ReturnRef_to_return_a_value);
        return Action<F>(new Impl<F>(ref_));
    }

private:
    // Implements the ReturnRef(x) action for a particular function type F.
    template<typename F>
    class Impl : public ActionInterface<F>
    {
    public:
        typedef typename Function<F>::Result Result;
        typedef typename Function<F>::ArgumentTuple ArgumentTuple;

        explicit Impl(T &ref)
            : ref_(ref)
        {
        } // NOLINT

        virtual Result Perform(const ArgumentTuple &)
        {
            return ref_;
        }

    private:
        T &ref_;

        GTEST_DISALLOW_ASSIGN_(Impl);
    };

    T &ref_;

    GTEST_DISALLOW_ASSIGN_(ReturnRefAction);
};

// Implements the polymorphic ReturnRefOfCopy(x) action, which can be
// used in any function that returns a reference to the type of x,
// regardless of the argument types.
template<typename T>
class ReturnRefOfCopyAction
{
public:
    // Constructs a ReturnRefOfCopyAction object from the reference to
    // be returned.
    explicit ReturnRefOfCopyAction(const T &value)
        : value_(value)
    {
    } // NOLINT

    // This template type conversion operator allows ReturnRefOfCopy(x) to be
    // used in ANY function that returns a reference to x's type.
    template<typename F>
    operator Action<F>() const
    {
        typedef typename Function<F>::Result Result;
        // Asserts that the function return type is a reference.  This
        // catches the user error of using ReturnRefOfCopy(x) when Return(x)
        // should be used, and generates some helpful error message.
        GTEST_COMPILE_ASSERT_(
            internal::is_reference<Result>::value,
            use_Return_instead_of_ReturnRefOfCopy_to_return_a_value);
        return Action<F>(new Impl<F>(value_));
    }

private:
    // Implements the ReturnRefOfCopy(x) action for a particular function type F.
    template<typename F>
    class Impl : public ActionInterface<F>
    {
    public:
        typedef typename Function<F>::Result Result;
        typedef typename Function<F>::ArgumentTuple ArgumentTuple;

        explicit Impl(const T &value)
            : value_(value)
        {
        } // NOLINT

        virtual Result Perform(const ArgumentTuple &)
        {
            return value_;
        }

    private:
        T value_;

        GTEST_DISALLOW_ASSIGN_(Impl);
    };

    const T value_;

    GTEST_DISALLOW_ASSIGN_(ReturnRefOfCopyAction);
};

// Implements the polymorphic DoDefault() action.
class DoDefaultAction
{
public:
    // This template type conversion operator allows DoDefault() to be
    // used in any function.
    template<typename F>
    operator Action<F>() const
    {
        return Action<F>();
    } // NOLINT
};

// Implements the Assign action to set a given pointer referent to a
// particular value.
template<typename T1, typename T2>
class AssignAction
{
public:
    AssignAction(T1 *ptr, T2 value)
        : ptr_(ptr)
        , value_(value)
    {
    }

    template<typename Result, typename ArgumentTuple>
    void Perform(const ArgumentTuple & /* args */) const
    {
        *ptr_ = value_;
    }

private:
    T1 *const ptr_;
    const T2 value_;

    GTEST_DISALLOW_ASSIGN_(AssignAction);
};

#if !GTEST_OS_WINDOWS_MOBILE

// Implements the SetErrnoAndReturn action to simulate return from
// various system calls and libc functions.
template<typename T>
class SetErrnoAndReturnAction
{
public:
    SetErrnoAndReturnAction(int errno_value, T result)
        : errno_(errno_value)
        , result_(result)
    {
    }
    template<typename Result, typename ArgumentTuple>
    Result Perform(const ArgumentTuple & /* args */) const
    {
        errno = errno_;
        return result_;
    }

private:
    const int errno_;
    const T result_;

    GTEST_DISALLOW_ASSIGN_(SetErrnoAndReturnAction);
};

#endif // !GTEST_OS_WINDOWS_MOBILE

// Implements the SetArgumentPointee<N>(x) action for any function
// whose N-th argument (0-based) is a pointer to x's type.  The
// template parameter kIsProto is true iff type A is ProtocolMessage,
// proto2::Message, or a sub-class of those.
template<size_t N, typename A, bool kIsProto>
class SetArgumentPointeeAction
{
public:
    // Constructs an action that sets the variable pointed to by the
    // N-th function argument to 'value'.
    explicit SetArgumentPointeeAction(const A &value)
        : value_(value)
    {
    }

    template<typename Result, typename ArgumentTuple>
    void Perform(const ArgumentTuple &args) const
    {
        CompileAssertTypesEqual<void, Result>();
        *::testing::get<N>(args) = value_;
    }

private:
    const A value_;

    GTEST_DISALLOW_ASSIGN_(SetArgumentPointeeAction);
};

template<size_t N, typename Proto>
class SetArgumentPointeeAction<N, Proto, true>
{
public:
    // Constructs an action that sets the variable pointed to by the
    // N-th function argument to 'proto'.  Both ProtocolMessage and
    // proto2::Message have the CopyFrom() method, so the same
    // implementation works for both.
    explicit SetArgumentPointeeAction(const Proto &proto)
        : proto_(new Proto)
    {
        proto_->CopyFrom(proto);
    }

    template<typename Result, typename ArgumentTuple>
    void Perform(const ArgumentTuple &args) const
    {
        CompileAssertTypesEqual<void, Result>();
        ::testing::get<N>(args)->CopyFrom(*proto_);
    }

private:
    const internal::linked_ptr<Proto> proto_;

    GTEST_DISALLOW_ASSIGN_(SetArgumentPointeeAction);
};

// Implements the InvokeWithoutArgs(f) action.  The template argument
// FunctionImpl is the implementation type of f, which can be either a
// function pointer or a functor.  InvokeWithoutArgs(f) can be used as an
// Action<F> as long as f's type is compatible with F (i.e. f can be
// assigned to a tr1::function<F>).
template<typename FunctionImpl>
class InvokeWithoutArgsAction
{
public:
    // The c'tor makes a copy of function_impl (either a function
    // pointer or a functor).
    explicit InvokeWithoutArgsAction(FunctionImpl function_impl)
        : function_impl_(function_impl)
    {
    }

    // Allows InvokeWithoutArgs(f) to be used as any action whose type is
    // compatible with f.
    template<typename Result, typename ArgumentTuple>
    Result Perform(const ArgumentTuple &)
    {
        return function_impl_();
    }

private:
    FunctionImpl function_impl_;

    GTEST_DISALLOW_ASSIGN_(InvokeWithoutArgsAction);
};

// Implements the InvokeWithoutArgs(object_ptr, &Class::Method) action.
template<class Class, typename MethodPtr>
class InvokeMethodWithoutArgsAction
{
public:
    InvokeMethodWithoutArgsAction(Class *obj_ptr, MethodPtr method_ptr)
        : obj_ptr_(obj_ptr)
        , method_ptr_(method_ptr)
    {
    }

    template<typename Result, typename ArgumentTuple>
    Result Perform(const ArgumentTuple &) const
    {
        return (obj_ptr_->*method_ptr_)();
    }

private:
    Class *const obj_ptr_;
    const MethodPtr method_ptr_;

    GTEST_DISALLOW_ASSIGN_(InvokeMethodWithoutArgsAction);
};

// Implements the InvokeWithoutArgs(callback) action.
template<typename CallbackType>
class InvokeCallbackWithoutArgsAction
{
public:
    // The c'tor takes ownership of the callback.
    explicit InvokeCallbackWithoutArgsAction(CallbackType *callback)
        : callback_(callback)
    {
        callback->CheckIsRepeatable(); // Makes sure the callback is permanent.
    }

    // This type conversion operator template allows Invoke(callback) to
    // be used wherever the callback's return type can be implicitly
    // converted to that of the mock function.
    template<typename Result, typename ArgumentTuple>
    Result Perform(const ArgumentTuple &) const
    {
        return callback_->Run();
    }

private:
    const internal::linked_ptr<CallbackType> callback_;

    GTEST_DISALLOW_ASSIGN_(InvokeCallbackWithoutArgsAction);
};

// Implements the IgnoreResult(action) action.
template<typename A>
class IgnoreResultAction
{
public:
    explicit IgnoreResultAction(const A &action)
        : action_(action)
    {
    }

    template<typename F>
    operator Action<F>() const
    {
        // Assert statement belongs here because this is the best place to verify
        // conditions on F. It produces the clearest error messages
        // in most compilers.
        // Impl really belongs in this scope as a local class but can't
        // because MSVC produces duplicate symbols in different translation units
        // in this case. Until MS fixes that bug we put Impl into the class scope
        // and put the typedef both here (for use in assert statement) and
        // in the Impl class. But both definitions must be the same.
        typedef typename internal::Function<F>::Result Result;

        // Asserts at compile time that F returns void.
        CompileAssertTypesEqual<void, Result>();

        return Action<F>(new Impl<F>(action_));
    }

private:
    template<typename F>
    class Impl : public ActionInterface<F>
    {
    public:
        typedef typename internal::Function<F>::Result Result;
        typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;

        explicit Impl(const A &action)
            : action_(action)
        {
        }

        virtual void Perform(const ArgumentTuple &args)
        {
            // Performs the action and ignores its result.
            action_.Perform(args);
        }

    private:
        // Type OriginalFunction is the same as F except that its return
        // type is IgnoredValue.
        typedef typename internal::Function<F>::MakeResultIgnoredValue
            OriginalFunction;

        const Action<OriginalFunction> action_;

        GTEST_DISALLOW_ASSIGN_(Impl);
    };

    const A action_;

    GTEST_DISALLOW_ASSIGN_(IgnoreResultAction);
};

// A ReferenceWrapper<T> object represents a reference to type T,
// which can be either const or not.  It can be explicitly converted
// from, and implicitly converted to, a T&.  Unlike a reference,
// ReferenceWrapper<T> can be copied and can survive template type
// inference.  This is used to support by-reference arguments in the
// InvokeArgument<N>(...) action.  The idea was from "reference
// wrappers" in tr1, which we don't have in our source tree yet.
template<typename T>
class ReferenceWrapper
{
public:
    // Constructs a ReferenceWrapper<T> object from a T&.
    explicit ReferenceWrapper(T &l_value)
        : pointer_(&l_value)
    {
    } // NOLINT

    // Allows a ReferenceWrapper<T> object to be implicitly converted to
    // a T&.
    operator T &() const { return *pointer_; }

private:
    T *pointer_;
};

// Allows the expression ByRef(x) to be printed as a reference to x.
template<typename T>
void PrintTo(const ReferenceWrapper<T> &ref, ::std::ostream *os)
{
    T &value = ref;
    UniversalPrinter<T &>::Print(value, os);
}

// Does two actions sequentially.  Used for implementing the DoAll(a1,
// a2, ...) action.
template<typename Action1, typename Action2>
class DoBothAction
{
public:
    DoBothAction(Action1 action1, Action2 action2)
        : action1_(action1)
        , action2_(action2)
    {
    }

    // This template type conversion operator allows DoAll(a1, ..., a_n)
    // to be used in ANY function of compatible type.
    template<typename F>
    operator Action<F>() const
    {
        return Action<F>(new Impl<F>(action1_, action2_));
    }

private:
    // Implements the DoAll(...) action for a particular function type F.
    template<typename F>
    class Impl : public ActionInterface<F>
    {
    public:
        typedef typename Function<F>::Result Result;
        typedef typename Function<F>::ArgumentTuple ArgumentTuple;
        typedef typename Function<F>::MakeResultVoid VoidResult;

        Impl(const Action<VoidResult> &action1, const Action<F> &action2)
            : action1_(action1)
            , action2_(action2)
        {
        }

        virtual Result Perform(const ArgumentTuple &args)
        {
            action1_.Perform(args);
            return action2_.Perform(args);
        }

    private:
        const Action<VoidResult> action1_;
        const Action<F> action2_;

        GTEST_DISALLOW_ASSIGN_(Impl);
    };

    Action1 action1_;
    Action2 action2_;

    GTEST_DISALLOW_ASSIGN_(DoBothAction);
};

} // namespace internal

// An Unused object can be implicitly constructed from ANY value.
// This is handy when defining actions that ignore some or all of the
// mock function arguments.  For example, given
//
//   MOCK_METHOD3(Foo, double(const string& label, double x, double y));
//   MOCK_METHOD3(Bar, double(int index, double x, double y));
//
// instead of
//
//   double DistanceToOriginWithLabel(const string& label, double x, double y) {
//     return sqrt(x*x + y*y);
//   }
//   double DistanceToOriginWithIndex(int index, double x, double y) {
//     return sqrt(x*x + y*y);
//   }
//   ...
//   EXPECT_CALL(mock, Foo("abc", _, _))
//       .WillOnce(Invoke(DistanceToOriginWithLabel));
//   EXPECT_CALL(mock, Bar(5, _, _))
//       .WillOnce(Invoke(DistanceToOriginWithIndex));
//
// you could write
//
//   // We can declare any uninteresting argument as Unused.
//   double DistanceToOrigin(Unused, double x, double y) {
//     return sqrt(x*x + y*y);
//   }
//   ...
//   EXPECT_CALL(mock, Foo("abc", _, _)).WillOnce(Invoke(DistanceToOrigin));
//   EXPECT_CALL(mock, Bar(5, _, _)).WillOnce(Invoke(DistanceToOrigin));
typedef internal::IgnoredValue Unused;

// This constructor allows us to turn an Action<From> object into an
// Action<To>, as long as To's arguments can be implicitly converted
// to From's and From's return type cann be implicitly converted to
// To's.
template<typename To>
template<typename From>
Action<To>::Action(const Action<From> &from)
    :
#if GTEST_LANG_CXX11
    fun_(from.fun_)
    ,
#endif
    impl_(from.impl_ == NULL ? NULL
                             : new internal::ActionAdaptor<To, From>(from))
{
}

// Creates an action that returns 'value'.  'value' is passed by value
// instead of const reference - otherwise Return("string literal")
// will trigger a compiler error about using array as initializer.
template<typename R>
internal::ReturnAction<R> Return(R value)
{
    return internal::ReturnAction<R>(internal::move(value));
}

// Creates an action that returns NULL.
inline PolymorphicAction<internal::ReturnNullAction> ReturnNull()
{
    return MakePolymorphicAction(internal::ReturnNullAction());
}

// Creates an action that returns from a void function.
inline PolymorphicAction<internal::ReturnVoidAction> Return()
{
    return MakePolymorphicAction(internal::ReturnVoidAction());
}

// Creates an action that returns the reference to a variable.
template<typename R>
inline internal::ReturnRefAction<R> ReturnRef(R &x)
{ // NOLINT
    return internal::ReturnRefAction<R>(x);
}

// Creates an action that returns the reference to a copy of the
// argument.  The copy is created when the action is constructed and
// lives as long as the action.
template<typename R>
inline internal::ReturnRefOfCopyAction<R> ReturnRefOfCopy(const R &x)
{
    return internal::ReturnRefOfCopyAction<R>(x);
}

// Modifies the parent action (a Return() action) to perform a move of the
// argument instead of a copy.
// Return(ByMove()) actions can only be executed once and will assert this
// invariant.
template<typename R>
internal::ByMoveWrapper<R> ByMove(R x)
{
    return internal::ByMoveWrapper<R>(internal::move(x));
}

// Creates an action that does the default action for the give mock function.
inline internal::DoDefaultAction DoDefault()
{
    return internal::DoDefaultAction();
}

// Creates an action that sets the variable pointed by the N-th
// (0-based) function argument to 'value'.
template<size_t N, typename T>
PolymorphicAction<
    internal::SetArgumentPointeeAction<
        N, T, internal::IsAProtocolMessage<T>::value>>
SetArgPointee(const T &x)
{
    return MakePolymorphicAction(internal::SetArgumentPointeeAction<
                                 N, T, internal::IsAProtocolMessage<T>::value>(x));
}

#if !((GTEST_GCC_VER_ && GTEST_GCC_VER_ < 40000) || GTEST_OS_SYMBIAN)
// This overload allows SetArgPointee() to accept a string literal.
// GCC prior to the version 4.0 and Symbian C++ compiler cannot distinguish
// this overload from the templated version and emit a compile error.
template<size_t N>
PolymorphicAction<
    internal::SetArgumentPointeeAction<N, const char *, false>>
SetArgPointee(const char *p)
{
    return MakePolymorphicAction(internal::SetArgumentPointeeAction<
                                 N, const char *, false>(p));
}

template<size_t N>
PolymorphicAction<
    internal::SetArgumentPointeeAction<N, const wchar_t *, false>>
SetArgPointee(const wchar_t *p)
{
    return MakePolymorphicAction(internal::SetArgumentPointeeAction<
                                 N, const wchar_t *, false>(p));
}
#endif

// The following version is DEPRECATED.
template<size_t N, typename T>
PolymorphicAction<
    internal::SetArgumentPointeeAction<
        N, T, internal::IsAProtocolMessage<T>::value>>
SetArgumentPointee(const T &x)
{
    return MakePolymorphicAction(internal::SetArgumentPointeeAction<
                                 N, T, internal::IsAProtocolMessage<T>::value>(x));
}

// Creates an action that sets a pointer referent to a given value.
template<typename T1, typename T2>
PolymorphicAction<internal::AssignAction<T1, T2>> Assign(T1 *ptr, T2 val)
{
    return MakePolymorphicAction(internal::AssignAction<T1, T2>(ptr, val));
}

#if !GTEST_OS_WINDOWS_MOBILE

// Creates an action that sets errno and returns the appropriate error.
template<typename T>
PolymorphicAction<internal::SetErrnoAndReturnAction<T>>
SetErrnoAndReturn(int errval, T result)
{
    return MakePolymorphicAction(
        internal::SetErrnoAndReturnAction<T>(errval, result));
}

#endif // !GTEST_OS_WINDOWS_MOBILE

// Various overloads for InvokeWithoutArgs().

// Creates an action that invokes 'function_impl' with no argument.
template<typename FunctionImpl>
PolymorphicAction<internal::InvokeWithoutArgsAction<FunctionImpl>>
InvokeWithoutArgs(FunctionImpl function_impl)
{
    return MakePolymorphicAction(
        internal::InvokeWithoutArgsAction<FunctionImpl>(function_impl));
}

// Creates an action that invokes the given method on the given object
// with no argument.
template<class Class, typename MethodPtr>
PolymorphicAction<internal::InvokeMethodWithoutArgsAction<Class, MethodPtr>>
InvokeWithoutArgs(Class *obj_ptr, MethodPtr method_ptr)
{
    return MakePolymorphicAction(
        internal::InvokeMethodWithoutArgsAction<Class, MethodPtr>(
            obj_ptr, method_ptr));
}

// Creates an action that performs an_action and throws away its
// result.  In other words, it changes the return type of an_action to
// void.  an_action MUST NOT return void, or the code won't compile.
template<typename A>
inline internal::IgnoreResultAction<A> IgnoreResult(const A &an_action)
{
    return internal::IgnoreResultAction<A>(an_action);
}

// Creates a reference wrapper for the given L-value.  If necessary,
// you can explicitly specify the type of the reference.  For example,
// suppose 'derived' is an object of type Derived, ByRef(derived)
// would wrap a Derived&.  If you want to wrap a const Base& instead,
// where Base is a base class of Derived, just write:
//
//   ByRef<const Base>(derived)
template<typename T>
inline internal::ReferenceWrapper<T> ByRef(T &l_value)
{ // NOLINT
    return internal::ReferenceWrapper<T>(l_value);
}

} // namespace testing

#endif // GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
